173813821 has 2 divisors, whose sum is σ = 173813822. Its totient is φ = 173813820.

The previous prime is 173813819. The next prime is 173813911. The reversal of 173813821 is 128318371.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125664100 + 48149721 = 11210^2 + 6939^2 .

It is a cyclic number.

It is not a de Polignac number, because 173813821 - 2¹ = 173813819 is a prime.

It is a super-2 number, since 2×173813821² = 60422488741240082, which contains 22 as substring.

Together with 173813819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (173810821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86906910 + 86906911.

It is an arithmetic number, because the mean of its divisors is an integer number (86906911).

Almost surely, 2^173813821 is an apocalyptic number.

It is an amenable number.

173813821 is a deficient number, since it is larger than the sum of its proper divisors (1).

173813821 is an equidigital number, since it uses as much as digits as its factorization.

173813821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 34.

The square root of 173813821 is about 13183.8469727163. The cubic root of 173813821 is about 558.0778283720.

The spelling of 173813821 in words is "one hundred seventy-three million, eight hundred thirteen thousand, eight hundred twenty-one".